That would be the next step. The reason being is because if the evap system were malfuntioning, then the check engine light would come on with an evap code. But since that is not happening, the evap system is working properly and then it is likley just to be an upstruction in the fuel filler neck.

Ok, a few other ways to diagnose this condition. Disconnect the large evap hose going to the canister (number 8 in the pic) and try filling up the fuel tank. If the problem remains, then the problem is before the canister and vent valve. If the problem goes away after removing this hose from the canister, then the problem is in or after the charcaol canister.

Ok, then the next step would be to remove the fuel filler neck and drop the fuel tank to look for obstructions. The problem is either going to be in/on top of the tank, fuel filler neck or the or the hose from the tank to the canister.